The term 'precipitant' can be defined as an action or event that causes a SUDDEN, UNEXPECTED, and often HASTY change. This term can be broken down into several synonyms, such as 'SUDDEN' (6 letters), 'EARLY' (5 letters), 'HASTY' (5 letters), 'UNEXPECTED' (10 letters), 'HEADLONG' (8 letters), 'HURRIED' (7 letters), and 'IMPETUOUS' (9 letters), as well as 'RASH' (4 letters). All of these words describe a situation in which a person or event causes a rapid and UNEXPECTED change.